The present invention relates to a side airbag apparatus that, when an impact equal to or greater than a predetermined value is applied to a vehicle body, is inflated and deployed between a sidewall of the vehicle body and an occupant seated on a seat of the vehicle.
Japanese Laid-Open Patent Publication No. 2002-362295 and Japanese Patent No. 2933894 disclose typical side airbag apparatuses. Such a side airbag apparatus, which is shown in FIG. 12, is typically embedded in a backrest 15 coupled to a seat portion 14 of a car seat 12. Specifically, the side airbag apparatus is embedded in a side of the backrest 15 that faces the outside of the vehicle. At a collision, the side airbag apparatus inflates and deploys an airbag 31 from the side of the backrest 15 and along a sidewall of the vehicle body, or between a door 16 and an occupant P.
When the inflation and deployment of the airbag 31 are completed, a portion of the airbag 31 that corresponds to an elbow portion Pe of the occupant P has a relatively large measurement along the lateral direction of the vehicle. Therefore, the airbag 31 excessively push the elbow portion Pe laterally inward. That is, an upper arm of the occupant P is excessively pivoted about the shoulder by the airbag 31. Accordingly, an excessive force is applied the chest of the occupant P.